Either take the GUE course series, or call yourself DIR, Hogarthian, (or possibly UTD) then.
A GUE diver is GUE trained and more. Things you cannot get from another agency's training or if you choose to remain a distant satellite to the organization. Despite having GUE training, I am not a GUE diver.
Evolution of DIR Principles | Global Underwater Explorers
So I could call myself a GUE diver after taking Fundies, but I can't call myself a GUE diver anymore since I took a TDI trimix course with a former GUE instructor?
Tom